Laboratory Study of the Deflector Effect of Flow Pattern on Water Retention and Debris Retention Efficiency

Accumulation of debris along with water flow in waterways causes irreparable problems every year. Structural methods are one of the most effective ways to reduce the risks of debris flow. In this study, the efficiency of the debris structure was investigated using flow pattern deflectors to increase the deposition retention efficiency and its effect on backwater and rapid collection of wood debris after the flood. To do this research, three different geometries of the rack, a debris mixture and three flow deflector sizes were used in the laboratory. According to the results, the best performance of the rack, despite the flow deflectors was related to the regular linear descaler with 97% efficiency and backwater was completely affected by the flow Froude Number. The V-shaped reverse rack had the lowest backwater rate of 2.55%, that is not significant. In this study, the length of the debris carpet and the maximum height of the middle mound produced for the rack geometry were investigated. The results showed that the deflector installation led to a change in the geometry of the deposited accumulation which also accelerates the debris collection operation after the flood.